Field of the Invention
The present disclosure relates to a transmission for a hybrid vehicle, and more particularly, to a transmission for a hybrid vehicle capable of increasing speed-shifting efficiency, improving fuel efficiency, and being driven in series and parallel modes by implementing speed-shifting multi-staging in electric vehicle (EV)/hybrid electric vehicle (HEV) driving modes.
Description of Related Art
A hybrid vehicle means a vehicle driven by efficiently combining two or more kinds of power sources with each other, and mainly means a vehicle driven by an engine obtaining a torque by burning fuel (fossil fuel such as gasoline, or the like) and an electric motor obtaining a torque by electric power of a battery.
The hybrid vehicle is the future vehicle including the engine and the motor to promote a decrease in exhaust gas and improvement of fuel efficiency, and research into the hybrid vehicle has been actively conducted in accordance with the demands of the times for improvement of fuel efficiency and development of an environmentally friendly product.
The hybrid vehicle is classified into a series type hybrid vehicle, a parallel type hybrid vehicle, and the like. Here, the series type hybrid vehicle is a hybrid system which includes the engine and the motor, but in which the engine generates only electricity and supplies the electricity to the motor and the battery and force for driving wheels driving the vehicle is provided by only the electric motor, and the parallel type hybrid vehicle has the engine and the motor both of which provide the force for driving the wheels.
Meanwhile, a hybrid vehicle capable of implementing both of series and parallel modes has been developed.
However, in the hybrid vehicle according to the related art, frictional elements using oil pressure, such as a clutch, a brake, and the like, are used in a transmission, such that speed-shifting efficiency and power transfer efficiency are decreased.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.